docs: def has_pathology_causal(graph: BELGraph, u: BaseEntity, v: BaseEntity, k: str) -> bool:
      """Check if the subject is a pathology and has a causal relationship with a non bioprocess/pathology.
  
      :return: If the subject of this edge is a pathology and it participates in a causal reaction.
      """
      return (
          isinstance(u, Pathology) and
          is_causal_relation(graph, u, v, k) and
          not isinstance(v, (Pathology, BiologicalProcess))
      )